1. Field of the Invention
This invention relates to brush bristles and brushes and more particularly to an improved composite bristle having a metallic inner component and a polymeric outer component.
2. Description of the Related Art
The prior art has known many types of brushes and brush bristles for use in various the applications. One important type of brush includes rotary brushes characterized by a central hub with a multiplicity of bristles extending radially outwardly from the central hub. Upon rotation of the central hub, the multiplicity of bristles rotate about the central hub to provide a wiping movement to a surface. Such type of rotary brushes are used for cleaning large surfaces application including industrial applications, airport landing strips, highways, parking lots, streets and the like. When a large rotary brush is adapted for cleaning a large surface area such as set forth above, the large rotary brush is mounted on a land vehicle such as a truck, tractor or the like. The following United States patents are representative of rotary cleaning machine of the prior art.
U.S. Pat. No. 3,005,274 discloses an apparatus for removing ballast from cribs between crossties of a railroad track comprising a mainframe having wheels to ride on the track and a digging implement frame over the crossties. A brush like digging unit is mounted for rotation on the implement frame on an axis generally normal to the crossties and having flexible members that extend below the crossties to dig ballast from the cribs. The implement frame is supported on the same from the upper surface of the crossties for moment across the crossties from one crib to the next.
U.S. Pat. No. 3,228,053 discloses a brush strip comprising an elongated flat metal plate having a series of apertures space there long. Metal collars having inner ends are integral with the plate around the apertures and have free ends extending outwardly on one side only of the plate. Tufts of bristles extend through the collar and the apertures. The bristles have free ends projecting beyond the free ends of the collars and looped ends projecting beyond, the other side of the plate. A retaining rod engages against the other side of the plate and extends through the looped end of the bristles. Elastomeric tubes surround the tufts of bristles along part of the length thereof. The tubes have inner end portions engaging between the tufts of bristles and the collars and the other end portions extending outwardly from the free ends of the collars and terminating between free ends of the collar and free ends of the bristles. The core assembly mounts the strips for rotation about an axle comprising a tube and a plurality of supports affixed in axially spaced relation along the tube. Means on the supports define a plurality of open-ended guideways for the strips. The guideways extend parallel to the axis at intervals spaced circumferentially about the arc of a circle. The means defining the guide ways each has a pair of opposed sides extending radially of the tube and angularly space from one another by distances greater than the width of the plates. Radial spaced elements extend substantially in the circumferential direction of the circle from inner and outer ends of the side surfaces, respectively. The stop elements at the outer ends of the side surfaces of each guideway terminates in an edge disposed toward and space from another by distances less than the width of the plates in greater than the diameter of the collars thereby providing clearance therebetween for the collars. The radial spacing of the stop elements are less than the distance between the other sides of the plates and the free ands of the collars whereby the collars and tubes protect the bristles from engagement against the stop surfaces at the outer ends of the side surfaces in the outer end portions of the tubes resiliently support the bristles against the bending about short radii adjacent to the free end of the collars.
U.S. Pat. No. 3,237,232 discloses a method of replacing worn gear teeth on a gear circle of the type having an annular metallic member enclosing a free on obstructed space. The annular metallic member has radially inwardly extending gear teeth at the inner periphery thereof. The method comprises forming a plurality of tooth metallic arcuate segments each having an outer periphery having a radius of curvature greater than the radius of curvature of a circle drawn through the points of connection of the teeth of the gear circle to the annular metallic member. Each of the segments has teeth of identical pitch to those carried by the gear circle. The segments collectively form a circle when placed in substantially end-to-end relationship to each other. All of the gear teeth are cut away from the gear circle by cutting through the gear circle along an annular reference line having a radius larger than the radius of curvature of the outer periphery of the arcuate segments. The arcuate segment is positioned in end-to-end circular array inside the outer peripheral portion of the gear circle in place of the removed inner peripheral portion thereof. The arcuate segments are secured to the outer peripheral portions of the gear circle while maintaining the circular array of the segments.
U.S. Pat. No. 3,649,984 discloses a bristle element especially adapted for use in a broom machine for a railway roadbed or track. The bristle elements are replaceably mounted on a mandrel rotatable on a horizontal axis. The bristle elements have a core made of a bundle of parallel straight spring-steel splines or wires fixed together at one end in a detachable coupling and encased in a resilient sheath which binds the splines into mutually supporting relation and distributes flexing stress in them away from their fixed end.
U.S. Pat. No. 4,144,610 discloses a bristle for mounting on a rotatable drum or shaft to form a sweeping device for use in maintaining railroad rails, ties, ballast and way. The bristle contains a length of wire rope with a lubricant within the interstices of the wire and strands of the rope. A low density polyethylene jacket is high compression extruded onto the exterior and into the intersticial area of the length of wire rope thereby containing and permanently sealing the lubricant within the wire rope, increasing the longitudinal stiffness of the rope, and effecting a mechanical interlock between the wire rope and the polyethylene jacket which both secures the strands of the rope together and secures the polyethylene jacket to the rope. A polyurethane jacket is extruded onto the exterior of the polyethylene jacket thereby stiffening the wire rope and polyethylene jacket, protecting the same from abrasion and cutting, and preventing splaying, unraveling or flaring of the bristle.
U.S. Pat. No. 4,184,223 discloses a sweeper bristle element adapted for use on a railway roadbed or track cleaner employing a rotating drum with element support means. The sweeper bristle element is comprised of a solid elastomeric stem preferably made of 80 durometer rubber. The stem extends substantially the length of the element and has upper and lower portions. A solid weighting mass forming a forward wearing surface and preferably made from 60 durometer rubber is attached to the lower portion of the stem. The upper portion of the stem engages the element support means and rotation of the drum imparts a centrifugal force on the stem and the knob causing loose material that contacts the element to be driven away from the element. The stem and knob are reinforced by fabric or spring steel. In a preferred embodiment, the knob and stem form a laminated, integral structure.
U.S. Pat. No. 4,285,737 discloses a method for clearing a railway roadbed of loose material employs elongate sweeper bristle elements, each element comprising a stem terminating in a knob portion which functions as a solid weighting mass and which forms a forward wearing surface. The method includes the steps of rotating a plurality of the sweeper bristle elements over the railway roadbed to be cleared so that the ends of the elements contact the loose material; imparting a centrifugal force on the stem and knob; and striking the loose material with the knob, thereby causing the loose material which contacts the knob to be driven away from the element. The preferred sweeper bristle elements are each comprised of a solid elastomeric stem preferably made of 80 durometer rubber. The stem extends substantially the length of the element and has upper and lower portions. A solid weighting mass forming a forward wearing surface and preferably made from 60 durometer rubber is attached to the lower portion of the stem. The upper portion of the stem engages a rotating drum. The rotation of the drum imparts a centrifugal force on the stem and the knob causing loose material that contacts the element to be driven away from the element.
U.S. Pat. No. 4,484,373 discloses an improved sweeper bristle element is disclosed especially adapted for use on a railway roadbed or track cleaner using a rotating drum onto which a plurality of bristles are fixedly supported. Each bristle element preferably includes an elastomeric stem of 80 durometer hardness with a toe of 60 durometer hardness wrapped around the end and one side of the stem. Rotation of the drum imparts centrifugal force on the bristles causing loose material contacting the toes thereof to be driven away. The stem and toe may be reinforced by fabric and/or spring steel and preferably are laminated together in a vulcanization process. The bristles are formed in a paddle-like configuration that increases the structural strength thereof and makes them simple to install on the drum. If desired, the bristle toe portion may be slitted to render the bristle adaptable to tight situations while maintaining the structural advantages of the paddle-like configuration.
U.S. Pat. No. 4,619,217 discloses an apparatus for cleaning underwater surfaces including at least one rotatable brush and pump for producing a stream of water from the front to the rear thereof. The brush and pump are axially reciprocable in a housing. The brush has bundles of bristles, each bundle having a head portion fitted into notches at the periphery of a main ring and held therein by a pinch ring, the main and pinch rings together constituting a brush base which is detachably secured to a rotatable base associated with the pump, by means of a pair of fixed members which are engagable upon relative rotation of the rotatable base and brush base.
U.S. Pat. No. 5,540,004 discloses an apparatus for removing ice and snow from a surface consisting of a support frame and a elongate member rotatably mounted on the support frame. The elongate member has a first end and a second end. A plurality of flexible arms extend from the elongate member in a substantially helical pattern. Upon rotation of the elongate member the arms violently strike a ground surface to dislodge packed snow and ice which is then carried by the helical pattern of the arms from the first end of the elongate member toward the second end.
Large rotary brushes for use cleaning large surfaces application are normally have a multiplicity of bristles formed from a metallic material or a multiplicity of bristles formed from a polymeric material. Each of these types of multiplicity of bristles has certain advantages over the other.
Large rotary brushes utilizing a multiplicity of bristles formed from a metallic material have the advantage of having an abrasive quality. Large rotary brushes utilizing a multiplicity of bristles formed from a polymeric material have the advantage of being stiffer than the multiplicity of bristles formed from a metallic material.
In an effort to combine the benefits of bristles formed from a metallic material and bristles formed from a polymeric material, the prior art has provided brushes having a multiplicity of bristles formed from a metallic material interposed between a multiplicity of bristles formed from a polymeric material. It would be desirable to combine the advantages of a metallic bristle and the advantages of a polymeric material in a single composite bristle. Unfortunately, none in the prior art have provided a composite wrestle having an inner metallic component and an outer polymeric component.
Therefore it is an object of this invention to provide a composite bristle having a metallic bristle inner component and a polymeric bristle outer component.
Another object of this invention is to provide an improved composite bristle that may be manufactured at a commercially economic price.
Another object of this invention is to provide an improved composite bristle that may be incorporated into various rotary cleaning machines.
Another object of this invention is to provide an improved composite bristle that may be adapted to rotary hubs of the prior art.
Another object of this invention is to provide an improved composite bristle with an extended life relative to large rotary brushes of the prior art.
Another object of this invention is to provide an improved composite bristle with superior cleaning characteristics.
The foregoing has outlined some of the more pertinent objects of the present invention. These objects should be construed as being merely illustrative of some of the more prominent features and applications of the invention. Many other beneficial results can be obtained by modifying the invention with in the scope of the invention. Accordingly other objects in a full understanding of the invention may be had by referring to the summary of the invention and the detailed description describing the preferred embodiment of the invention.